polymorphs Bi2O3 metastable thermotropic Anandamide temperature aluminide martensite recrystallization MgH2 lyotropic NbO2 antiaromatic tetrameric HQdgform GeSbTe tetragonal cristobalite phase thermoclines volatilizes Mg2SiO4 D3h tetracarbonyl recrystallizes magnetocrystalline enthalpy ferroelectric dissipative TQundL liquidus crystallinity nematic GQdgform ferromagnetic UCl3 eutectic poling